Method of converting air conditioning systems



March 11, 1952 H. H. HERMAN METHOD OF CONVERTING AIR CONDITIONINGSYSTEMS Filed Dec. 24, 1945 INVENTOR.

ATTO EV Patented Mar. 11, 1952 METHOD OF CONVERTING AIR CONDITION- INGSYSTEMS Harry H. Herman, Denver, Colo.

Application December 24, 1945, Serial No. 637,132

Claims.

This invention relates to a method of producing a cooling system, whichmay also be utilized for heating purposes, and more particularly to amethod of producing a cooling system for a building, or the like, whichcomprises the conversion of a conventional two-pipe steam heatingsystem.

A conventional two-pipe steam heating system consists of a steam supplymain provided with steam by a boiler or the like, and a plurality ofradiators connected with the steam main by branch pipes, risers and thelike, and also similarly connected with a return or condensate main forconducting condensate back to the boiler. Such a heating system,however, cannot be utilized in.the summer or other warm periods of theyear for cooling purposes. Also, if a cooling medium is circulatedthrough the supply main to the radiators, moisture tends to condense onthe radiators and produce pools of water between Furthermore, a heatradiator is dethe same. signed primarily for heating, and is relativelyinefiicient for cooling purposes,

Among the objects of this invention are to provide a novel method ofproducing a cooling system for buildings and the like; to provide such amethod which produces a cooling system which efficiently and effectivelycools the rooms or enclosed spaces of a building or the like; to providesuch a method which comprises the conversion of a conventional two-pipesteam heating system; to provide such a method whereby the conversion issimple and economical; and to provide such a method which produces acooling system which also may be utilized for heating purposes. I

The above and other objects, and the novel features of this invention,will become apparent from the accompanying drawing, in which:

Fig. 1 is a partially diagrammatic elevation illustrating a conventionaltwo-pipe steam heating system;

Fig. 2 is a partially diagrammatic elevation illustrating a preferredembodiment of this invention; and

Fig. 3 is a vertical cross section taken through a special shunt valveutilized in the system of Fig. 2.

A conventional two-pipe steam heating system as in Fig. 1, includes asteam supply main 9 to which steam may be supplied by a boiler or thelike, normally installed in a basement of the building, and from whichone or a plurality of risers l0 carry steam to various portions of thebuilding. From each riser l0, steam branch lines ll lead to radiators Rat the various floor levels,

each steam branch line H being connected with the inlet of a radiator,and the flow therethrough being controlled by a valve 12. The steamcondenses in the radiator R, and the condensate is returned through abranch line l3 to a return pipe M, a suitable thermostatic valve l5normally being installed at the outlet of the radiator R to insure thatonly condensate will pass out of the radiator. A plurality of returnpipes !4 may lead to a return main for returning the condensate to theboiler. Return pipe 14 is smaller in site than riser l0, since steamoccupies a considerably greater volume than condensate from the steam.The above system is conventionally used in heating buildings, eachradiator thus being placed in a suitable position, as upon a floor IS ina room, hallway, or other portion of the building.

It will be understood, of course, that main 9 may extend to the upperportion of the building, and the upper ends of risers I0 may beconnected therewith, the inlet of such a riser being at the upper endand the outlet at the lower end. Such risers are termed down risers,since the radiators supplied thereby are successively lower in thebuilding. Thus, as used in the appended claims, the term riser includesboth up risers and down risers, unless obviously inappropriate,

and the term supply main may include also one or more risers or otherpipes supplying cooling or heating units.

In accordance with the method of this invention, as in Fig. 2, aneifective cooling system, which also may be used for heating purposes ifdesired, is produced by a few relatively simple changes in theconventional heating system of Fig. 1. These changes include merely thesubstitution of cooling (and heating) units U for radiators R; theaddition of a single linea return main l1, preferably connected to theoutlet end of each riser I0; and the installation of suitable shuntmeans, such as a shunt valve V, in riser ill at each floor level orother desired position, such as just above each branch line H.

Each cooling unit U includes a heat transfer element, such as a coil l9,disposed within a housing 20 and adapted to cool air passing thereoverto be circulated into and through the room, as by fans 2| driven by amotor 22. The air may be taken into the housing through a'grill-work orlouvres at the ends or sides of the housing 20 and discharged into theroom through a grillwork or louvres 23 in the top of housing an, al-

though any other suitable position for the same may be selected forcooling and air condition 66 ing the room or enclosure. The method ofthis invention further includes the installation of a drip pan 25beneath coil 19 of each cooling unit U, for receiving moisturecondensing on coil 19, and connecting each drip pan with return pipe Itby a branch pipe 26. Return pipe !4 is thereby utilized in the system ofFig. 2 as a drain line, and therefore leads to a suitable main connectedwith a drain, sewer, or the like.

A cooled heat transfer liquid, normally water, is supplied main 9 by acooling or refrigeration apparatus 2'], preferably located in thebasement, or at any other convenient location. Cooling apparatus 2'! maybe conventional, and as such may operate in any one of several differentways, such as a compression refrigeration cycle wherein the motive poweris supplied by an electric or other motor, or an absorptionrefrigeration cycle wherein the motivating energy is supplied by a gasflame or the like. In apparatus 21, the water to be circulated throughthe units U is passed in heat transfer relationship with a coolingmedium, such as brine, expanded refrigerant gas or the like.

From cooling apparatus 21, the cooled liquid passes through a pipe 28 tomain 9 in which is installed a pump 29 to insure an adequate circulationof the cold water through the main 9, risers l0, and individual units U.As the cold water passes upwardly in riser It), usually to the first ofa series of units U, a portion thereof is shunted by valve V throughbranch pipe I I which may supply one or more units U, each through aninlet pipe 30 connected with coil 13. A hand valve 32 and a thermostaticvalve 33 may be installed in each inlet pipe 30, to provide additionalregulation of flow through the units U. r, either of valves 32 or 33 maybe installed alone. After passing through the coil, the water isreturned to riser i ll by an outlet pipe 3|, connected to riser adjacentthe outlet side of valve V, such as just above the valve. As will beevident, each branch pipe II is connected to riser I0 adjacent the inletof a valve V.

It will be understood, of course, that risers l0 may be down risers, inwhich event main 9 is connected thereto at their upper ends and returnmain I! at their lower ends. Or, a combination of up risers and downrisers may be utilized.

The valve V may be constructed, as in Fig. 3, with a globular body 35and a disc or butterfly valve 36, pivoted on a longitudinal pin 31. Disc36 is operable by turning from outside the valve body to force anydesired portion of the cold water through inlet pipe. 30. For unitscloser to the cooling apparatus 21, the shunt valve V will usually beset so as to offer less resistance to the flow of water through riserIll, and thereby divert less cold water through inlet 30, since asmaller rate of flow through the unit is required, due to the lowertemperature of the cold water. After effecting cooling and airconditioning in the room or other portion of the building in which theunit U is installed, the water, now warmer, is returned to riser illthrough outlet pipe 3|.

After all of the units U have been supplied with cooled water in theabove manner, the warmed water passes from the upper end of riser ill toreturn main I! and then downwardly through return main l! to the coolingapparatus 21. A valve 39 may be installed in each riser l0 adjacentreturn main H, to regulate the flow through the individual risers, so asto insure an adequate flow to each unit U.

The system produced by this invention may also be adapted for heatingpurposes, a boiler 40 being utilized instead of the cooling apparatus 21to supply hot water to main 9 through pump 29. Boiler 40 is connected bya pipe 4| with return main I1 and by a pipe 42 with supply main 9, andis adapted to heat water to a desired tem-- perature, for circulationthrough units U, valves V functioning as before to divert portions ofthe hot water through the units U, and the used water being returned tothe boiler through return main l1. Pump 29 is preferably utilized duringheating, to insure an adequate flow of hot Water to all units U. Valves43 are installed in return main l1 and main 9, respectively, forshutting off the flow through cooling apparatus 21 when boiler 40 is inuse, and valves 4:2 are installed in pipes M and 42, respectively, for asimilar purpose.

From the foregoing, it will be apparent that the method of producing acooling system in accordance with this invention, which system also maybe utilized for heating purposes, fulfills to a marked degree theobjects and requirements hereinbefore set forth. A valuable feature ofthis invention is the low cost of installation and the simplicity ofchange-over, as well as the effectiveness in operation of the units U,both for cooling and heating. Furthermore, the method of this inventionutilizes a maximum of piping already installed, and does not require theelimination of any such piping. Due to'the use of a maximum amount ofpiping already installed, the cost of the change-over is only a fractionof that which would be required for the installation of new piping for acooling, or cooling and heating system. Also, the cost of additionalequipment is relatively low, when compared with the greatly increasedfacilities for comfort afforded the occupants of the building.

It will be evident that the units U may be varied, both in design and inmanner of operation, and that different means for insuring the flow ofcold liquid through the coils is may be utilized, and further thatdifferent heat transfer elements, such as finned tube-type elements, maybe utilized in lieu of coils 19. It will also be evident that returnmain I! may be installed so as to be connected to outlet lines 3!, thuseliminating shunt valves V. However, the former return pipe I4 willstill be utilized as a drain line, since it is not large enough tohandle the volume of liquid passing through units U for coolingpurposes.

What is claimed is:

l. A method of converting a two-pipe steam heating system into a coolingor heating system for a building, said two-pipe steam heating systemincluding a steam supply main having one or more risers, branch linesleading to steam radiators at various floor levels, at least onecondensate return pipe, and branch return pipes leading from eachradiator to a condensate return pipe, said method comprising the stepsof installing cooling means for a heat transfer liquid and connectingthe same with said supply main; substituting cooling units for saidradiators, each said cooling unit including a heat transfer element;installing a drip pan beneath each heat transfer element for collectingmoisture condens ing on said heat transfer element; connecting each saiddrip pan with a former condensate return line, thereby converting theformer condensate return line into a drain line; connecting said drainline to a sewer or the like; installing a shunt valve in a riser at apoint adjacent each cooling unit; connecting the inlet of the heattransfer element of each said cooling unit with a riser at one side of ashunt valve; connecting the outlet of each said heat transfer unit withsaid riser at the opposite side of said shunt valve; and installing areturn line for conveying said heat transfer liquid from the ends ofsaid risers to said cooling means.

2. A method of converting a two-pipe steam heating system into a coolingor heating system for a building, said two-pipe steam heating systemincluding a steam supply main having one or more risers, branch linesleading to steam radiators at various floor levels, at least onecondensate return pipe, and branch return pipes leading from eachradiator to a condensate return pipe, said method comprising the stepsof installing cooling means for a heat transfer liquid and connectingthe same with said supply main; substituting cooling units for saidradiators, each said cooling unit including a heat transfer element;installing drip pans for collecting moisture condensing on said heattransfer elements; connecting each said drip pan with a formercondensate branch line, thereby converting the former condensate returnline into a drain line; in-

stalling a shunt valve in a riser at each floor level; connecting theinlet of the heat transfer element of each said cooling unit with ariser at one side of a shunt valve; connecting the outlet of each saidheat transfer unit with said riser at the opposite side of said shuntvalve; and installing a return line for conveying said heat transferliquid from the ends of said risers to said cooling means.

3. In the production of a cooling or heating system for a building, suchsystem having a plurality of cooling units, each including a heattransfer element and a drip pan for collecting moisture condensing onsaid heat transfer element, the improvement which comprises converting atwo-pipe steam heating system which includes a steam supply main havingone or more risers, branch lines leading to steam radiators at variousfloor levels, at least one condensate return pipe, and branch returnpipes leading from each radiator to a condensate return pipe; saidconversion including the installation of cooling means for a heattransfer liquid and connecting the same with said supply main;substituting said cooling units for said radiators, said substitutionincluding the installation of said drip pans; installing shunt means ina riser at least at each floor level; connecting the inlet of the heattransfer element of each said cooling unit with a riser at one side of ashunt means;

connecting the outlet of each said heat transfer unit with said riser atthe opposite side of said shunt means; connecting each said drip panwith a former condensate return line, thereby converting the formercondensate return line into a drain line; and installing a return linefor conveying said heat transfer liquid from the ends of said risersback to said cooling means.

4. In the production of a cooling and air conditioning system for abuilding, also usable for heating purposes, such system having aplurality of cooling and heating units, each including a heat transferelement and a drip pan for collecting moisture condensing on said heattransfer element, the improvement which comprises converting a two-pipesteam heating system which includes a steam supply main having one ormore risers, steam branch lines leading to steam radiators at variousfloor levels, at least one condensate return pipe, and branch returnpipes leading from each radiator to a condensate return pipe; saidconversion including the installation of cooling means for a heattransfer liquid and connecting the same with said supply main;installing heating means for said heat exchange liquid and connectablealternatively to said supply main; substituting said cooling and heatingunits for said radiators; installing shunt means in a riser at least ateach floor level; connecting the inlet of the heat transfer element ofeach said cooling and heating unit with a riser below said shunt means;connecting the outlet of each said heat transfer unit with said riserabove said shunt means; connecting each said drip pan with a formercondensate return line, thereby converting the former condensate returnline into a drain line; and installing a return line for conveying saidheat transfer liquid from the ends of said risers to said cooling means,and alternatively to said heating means.

5. In the production of a cooling system for a building, such systemhaving a plurality of cooling units at each floor level, each coolingunit including a heat transfer element, and a drip pan for collectingmoisture condensing on said heat transfer element, the improvement whichcomprises converting a two-pipe steam heating system which includes asteam supply main having one or more risers, branch lines leading tosteam radiators at various floor levels,

at least one condensate return pipe, and branch return pipes leadingfrom said radiators to a condensate return pipe; said conversionincluding the installation of cooling means for a heat transfer liquidand connecting the same with said supply main; substituting said coolingunits for said radiators, including the installation of said drip pans;installing shunt valves in a riser at points adjacent said cooling unitsand at the different floor levels; connecting the inlet of the heattransfer element of each said cooling unit with a riser below a shuntvalve; connecting the outlet of each said heat transfer unit with saidriser above said shunt valve; connecting each said drip pan with aformer condensate return line, thereby converting the former condensatereturn line into a drain line; and installing a return line forconveying said heat transfer liquid from the ends of said risers to saidcooling means.

HARRY H. HERMAN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,065,415 Wild et al. June 24,1913 1,315,766 Feldman Sept. 9, 1919 1,979,941 Jewell Nov. 6, 19342,078,295 Thatcher Apr. 27, 1937 2,307,422 Richards Jan. 5, 1943

